If you've ever gone on vacation and done something a little more adventurous than you normally would, this story will make you think twice about it. A father of two was recently killed when he and a pal climbed into a giant inflatable ball that was then rolled down a snowy mountainside in a sport called "zorbing." The ball was supposed to lumber to a stop at the bottom of a small hill, but instead it veered off-course and went over a cliff, killing the father, Denis Burakov, and severely injuring his friend.

In the horrifying accident, caught on videotape by a friend of the pair, the ball rolls gently down a small incline, but then suddenly veers to the right with the men inside. Shortly afterwards, it veers again to the left, and this time it goes over the path and keeps going. It then disappears from view.

The comments made on the video are in Russian, but the Daily Mail translates them. One man is reportedly heard saying, "Oh f***, it's gone in the wrong direction again." And when someone else asks what's happening, a man reportedly replies: "Nothing." And then: "A catastrophe."

It's easy to be judgemental and say these men shouldn't have been so careless -- but who hasn't done some kind of slightly dangerous activity you normally wouldn't do while on vacation? I'm normally a very conservative person and not one for extreme sports of any kind, but on a recent vacation, I went snorkeling, wind sailing, and rope swing diving. None of these sports are particularly dangerous, but all of them came with their risks. It wasn't for nothing that the companies running the activities made me sign waivers releasing them from liability if anything bad happened.

During the snorkeling -- done in shallow but strong waters -- a sudden storm came along, leaving me clinging to a buoy until it passed. During the wind sailing, the sail was ripped from my hands by a gust of wind and ended up hitting me in the head. Two girls also taking lessons with me were suddenly whisked out to sea by a strong riptide and had to be rescued with a boat. Things happen. But who wants to stay in their hotel room all day? You see all of the companies offering these sports, and all of the people (including children) doing them and you assume they're safe.

I truly feel for this man's wife and children. Zorbing looked fun. In all honesty, I probably would have done it myself.